This group of insects contains many subgroups of wasps, and and also bees and ants, which evolved from wasp ancestors.
There are many different sizes in this group. Some parasitic wasps are so small they can develop into adults inside the eggs of other insects. Others are large and strong predators, over 3 cm long. All have chewing mouthparts, and the adults have a thin connection between their last two body sections (the abdomen and the thorax). All have 4 clear wings as adults, with the front pair larger than the back pair (queen and male ants have wings too, but only for a short time. Bees and wasps have straight antennae, ants often have a permanent bend in theirs.
Parasitic wasps often have a very large needle-like structure at the end of their abdomen. This isn't a stinger, its an ovipositor. They use it to inject their eggs inside a host insect, and some drill through bark, wood, or plant stems to get to their victims. These wasps mostly cannot sting, and they do not have the black and bright yellow colors that you may already know about.
Other wasps are predators, biting and stinging other insects and spiders. The wasps eat them, or carry their prey to their to feed their young. Wasps that sting are usually brightly colored with black and yellow stripes, sometimes red. This is a warning to potential predators that they can sting.
This is the second most diverse group of insects, only beetles are more diverse. There are over 200,000 species of wasps and their relatives known around the world, and probably at least that many still unknown to science. There are hundreds of species of wasps, bees, and ants here in Michigan.
Wasps and their kin are found all around the world.
Wasps, Bees and Ants are found in just about every habitat on land, except only the coldest polar regions.
Wasps and their relatives all have complete metamorphosis. From the egg a larva hatches out. It looks a lot like a short fat white worm, but has a distinct head, and may have six small jointed legs. The larva grows and molts (sheds its whole skin) several times before transforming into a pupa. This resting stage has some of the body parts of an adult, but it can't move or feed. Inside, it is transforming into an adult. Eventually an adult emerges from its pupal skin.
Female wasps, bees, and ants can lay dozens to many thousands of eggs, depending on the species. Unless they are parasites they make a nest, and supply their larvae with food to eat.
Some species in this group form colonies where only one or a few females (called queens) lay eggs, and the other females in the colony do not reproduce. Instead they take care of the queens' offspring. A few times a year, some of the offspring fly away to start new colonies.
Females in this group do a lot of parental care. In most species each female builds her own nest, and collects a food supply for each of her offspring. In some species they work cooperatively to build a nest and collect food, and in some species many females tend their sisters and brothers and don't reproduce themselves.
Most wasps live less than one year, some workers for just a few months. Queens sometimes live for several years.
Most wasps are active during daylight hours. They are active creatures, following scents to find their food. As noted in the reproduction section, some species live together in nests of relatives. No wasps migrate: if it regularly gets too cold or dry where they live, they go dormant until conditions improve.
These insects depend on chemical communication (taste/smell), but they also use other means. Males and females find each other with scent chemicals called pheromones, and ants and social wasps and bees use chemicals to identify nestmates and send warnings and other information. Parasitic wasps sometimes leave scent marks on the host insects to tell any other parasitic wasps that they've already laid eggs there. Some ants can also make noises and vibrations to communicate. Of the three groups, wasps are the most visual. They often hunt by sight.
Most non-parasitic wasps are predators and scavengers. They feed on dead animals, or hunt insects and spiders, and use their sting to paralyze their prey. They eat their prey themselves or bring some back to the hive to feed growing larvae. Some make individual cells, and put a supply of paralyzed prey animals in there along with an egg. The larva hatches and there is all the food they need. In general wasps are attracted to sugary foods like fruit or high protein foods like meat.
Some wasp species have larvae that eat plants the same way that caterpillars do.
Wasps are best known for their ability to give a painful sting, and lots of species do use their stingers to defend themselves and their nests. They also build their nests in places that are hard for predators to reach (either up high or underground) and many build nests out of hard mud to keep their larvae safe. Some wasps that attack other bees or wasps have especially hard exoskeletons for armor.
Wasps are important predators of other insects. Some species are valuable pollinators, and their relatives the bees are the most important pollinators of all.
Some of these species have a painful sting. The social nesting species can actually be dangerous to people: if someone disturbs their nest, they may sting them so many times that the person's life is endangered. Also, some wasps attack beneficial insects like bees.
In general this group of organisms has much more positive effects than negative. They are important enemies of many insect pests, helping protect our crops. They are also important pollinators, allowing our flowers and vegetables to grow and reproduce.